Last year investor Peter Thiel surprised a lot of people in the energy sector by calling cleantech investing “a disaster” and saying clean energy innovation has been a failure. However, fast forward about nine months, and Thiel just announced that he’s the largest investor in a new potentially $1 billion growth fund that will back companies across sectors including in energy and those tackling resource constraints.

The new fund, which already closed on $402 million, is called Mithril Capital Management after a type of metal described in J.R.R. Tolkien’s The Lord of Rings. Investors Ajay Royan and Jim O’Neillwill help co-manage the fund.

Best of luck to them. Backing companies that are looking to solve large problems in slow-moving industries like energy has tended to take longer, need more money, and just prove more difficult to fund than backing, say, web and mobile software startups. That’s why investors like Kleiner Perkins, Draper Fisher Jurvetson and Index Ventures have grown increasingly cold on cleantech.

“The best founders want to radically change the world for the better. To many investors, visionary entrepreneurs come off as naïve or worse — isn’t it safer/easier/more profitable to create a(nother) social network for cat fanciers. . . “

Royan tells All Things D that it will invest in “the non-fashionable companies,” so don’t expect social media or cloud investments from them.